PREPARATION AND MAGNETIC-PROPERTIES OF (ZN-SN) SUBSTITUTED BARIUM HEXAFERRITE NANOPARTICLES FOR MAGNETIC RECORDING

Zn-Sn substituted barium ferrite particles BaFe12-2xZnxSnxO19 with 0 l ess than or equal to x less than or equal to 1.1 have been prepared by a chemical co-precipitation method for the first time. X-ray diffract ion (XRD) and transition electron microscopy (TEM) have been carried o ut to determine the particle structure and morphology. Magnetic proper ties have been measured using a vibrating sample magnetometer (VSM) wi th an applied field up to 80 kOe. The specific saturation magnetizatio n M-s was determined using the law of approach to saturation, and the effective anisotropy field H-a and anisotropy constant K-1, were also estimated. It was found that the particle size could be effectively de creased and coercivity H-c easily controlled, by varying x without sig nificantly decreasing saturation magnetization. In particular, BaFe12- 2xZnxSnxO19 with x = 0.7-1.1 has suitable magnetic characteristics and a particle size small enough for high-density magnetic recording. (C) 1998 Elsevier Science B.V. All rights reserved.